Abstract: Apparatus and method are disclosed for monitoring the condition of a basic oxygen furnace (BOF) trunnion bearing. A shaft attached to a basic oxygen furnace (BOF) vessel is supported on either vessel side by a radial bearing which allows rotation of the shaft with respect to those bearings. One of the radial bearings is in turn mounted to a ladder bearing which allows shaft expansion and contraction with temperature. A Hall Effect transducer is mounted on both bearing sides to monitor the distance between the shaft and the transducer. If an output from the transducer deviates from a predetermined range the shaft position has shifted. This shift is an indication that either the radial or ladder bearing has or may in the near future fail. The apparatus therefore provides a warning that either replacement or repair of the BOF vessel trunnion bearing may be required.